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Summary of Vanya Darakchieva's activities

Research

I am working on the development of novel semiconductor and nanoscale materials, and spectroscopic metrology for ultra-fast electronics and optoelectronics that will greatly improve computation and communication capabilities. A major goal is to produce significant progress in understanding of epitaxial graphene properties towards device-grade epitaxial graphene for implementation in high-speed electronics and THz-frequency large scale processor technologies. To achieve this I apply unique ellipsometry techniques to study, understand and optimize the transport, electronic and structural properties of epitaxial graphene grown on SiC by sublimation.  Further current efforts are concentrated on understanding the mechanisms that generate and control the transport properties in epitaxial layers of group-III nitrides (InN, InAlN, AlGaN) for high-power electronic applications and novel solid state lighting. Most recent work focuses on building a THz ellipsometer, which will be the core of a unique THz and magneto-ellipsometry center at Linköping University. The unprecedented capabilities of this new instrumentation are the gathering meaningful information about electronic and spin transport with no physical contacts that can result in surface damage or sample contamination. The technology would be the first of its kind in Europe and could transform research into advanced semiconductor-, nano-, and bio-materials.  More about my research...

Our newly completed Terahertz ellipsometer

Selected publications

  • Assessing structural, free-charge carrier, and phonon properties of mixed-phase epitaxial films: The case of InN 
    M.-Y. Xie, M. Schubert, J. Lu, P. O. Å. Persson, V. Stanishev, C. L. Hsiao, L. C. Chen, W. J. Schaff, and V. Darakchieva
    Phys. Rev. B 90, 195306 (2014)
  • Large-area micro-focal ellipsometry mapping of thickness and electronic properties of epitaxial graphene on Si- and C- faces of 3C-SiC(111) 
    V. Darakchieva, A. Boosalis, A. A. Zakharov, T. Hofmann, M. Schubert, T. E. Tiwald, T. Iakimov, R. Vasiliuskas, and R. Yakimova
    Applied Physics Letters 102, 213116 (2013)
  • Elastic constants, composition and piezoelectric polarization of InAlN: from ab initio structural calculations to experimental implications for the validity of Vegard's rule
    M.-Y. Xie, F. Tasnádi, I. A. Abrikosov, L. Hultman and V. Darakchieva
    Physical Review B 86, 155310 (2012)       (pdf available)
  • Temperature dependent effective mass in AlGaN/GaN high mobility transistor structures
    T. Hofmann, P. Khüne, S, Schöche, Jr-Tai Chen, U. Forsberg, E. Janzén, N. Ben Sedrine, C. M. Herzinger, J. A. Woollam, M. Schubert, and V. Darakchieva
    Appl. Phys. Lett. 101, 192102 (2012)            (pdf available)
  • Anisotropic strain and phonon deformation potentials in GaN
    V. Darakchieva, T. Paskova, M. Schubert, H. Arwin, P. P. Paskov, B. Monemar, D. Hommel, J. Off, F. Scholz, M. Heuken, B. A. Haskell, P. T. Fini, S. J. Speck, S. Nakamura
    Physical Review B 75, 195217 (2007)

Complete list of publications...

Current supervision of students

 PhD students
  • Kevin Mead, main supervisor (2016- present)
  • Nerijus Armakavicius, main supervisor (2014-present)
  • Ingemar Persson, co-supervisor (2014-present)

List including former students... 

Current projects and funding

  • VINNOVA Competence Centre: Centre for III-nitride technology (C3NiT), principal investigator (2017-2022)
  • VR Consolidator Grant: Terahertz optical Hall effect in materials for next generation high speed and high power electronics (TeraNext), principal investigator (2017-2022)
  • SSF Research Infrastructure Fellow: Center for terahertz materials analysis, principal investigator (2016-2020)
     
  • SSF Future Research Leaders grant: THz ellipsometry of advanced materials for high-speed electronicsprincipal investigator (2014-2018)
     
  • VR Junior Researcher Grant: Taming graphene for ultra-high-speed electronics: insights from novel ellipsometry techniquesprincipal investigator (2014-2017)
     
  • ÅForsk: Terahertz Ellipsometer: the core of a new Terahertz Materials Preparation and Analysis Centerprincipal investigator (2014-2015)
     
  • Swedish Innovation Agency VINNOVA - VINNMER –  Marie Curie international qualification: THz ellipsometry and optical Hall effect: important techniques to study graphene and InNprincipal investigator (2012-2017)
     
  • VR: Free-charge carrier properties and doping mechanisms of advanced semiconductor materials for high speed and THz electronicsprincipal investigator (2011-2013)
     
  • National Science Foundation (FCT) Portugal: Free-charge carrier properties and doping mechanisms in InN-based materialsprincipal investigator (2010-2013)

Current teaching

Pedagogy courses

PhD courses

  • Semiconductor Physics I (8 ECTS)
  • Semiconductor Physics II (8 ECTS)
  • Advanced semiconductor materials (10 ECTS)
  • Carbon based materials and related low-dimensional systems (7 ECTS)

 


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Last updated: 05/16/17